JP7180129B2 - Ultrasound equipment and electronics - Google Patents

Description

The present invention relates to ultrasonic devices and electronic equipment.

An ultrasonic device is used to measure the distance to an object to be measured. Ultrasound devices transmit ultrasound waves and receive reflected waves. In addition, a device that emits ultrasonic waves from an ultrasonic device and measures the number of sheets of media by using the intensity of the ultrasonic waves that have passed through the sheet-shaped media is used. An ultrasonic device used for these devices is disclosed in Patent Document 1. According to it, an SOI substrate (Silicon on Insulator) is used for the ultrasonic device. A recess is formed in a part of the SOI substrate, and the SOI substrate is thin in the recess. An ultrasonic element is placed on this thin portion. This thin portion is called a diaphragm or membrane.

An ultrasonic element has a structure in which a piezoelectric thin film is sandwiched between electrodes. An ultrasonic element with this structure can be used for transmitting and receiving ultrasonic waves. When transmitting ultrasonic waves, the piezoelectric thin film bends when a voltage is applied between the electrodes. A predetermined voltage waveform is applied between the electrodes. At this time, the membrane vibrates. When the voltage application between the electrodes is stopped, the vibration of the membrane is damped and stopped. The transmitted ultrasonic waves are attenuated as the vibration of the membrane is attenuated. A thin attenuation absorbing film is placed over the ultrasonic element. This damping/absorbing film can absorb the vibration of the membrane and suppress the reverberation vibration. Therefore, since the vibration of the membrane is attenuated in a short time, the transmitted ultrasonic waves are attenuated in a short time.

When the ultrasonic element receives ultrasonic waves, the ultrasonic waves vibrate the membrane. Then, the piezoelectric thin film bends. At this time, a voltage is generated between the electrodes. By detecting the voltage between the electrodes, it can be recognized that the ultrasonic element has received the ultrasonic wave. At this time, since the damping absorption film suppresses the reverberant vibration, the ultrasonic wave can be converted into an electric signal with good responsiveness.

Japanese Patent Application Laid-Open No. 2007-37006

In the ultrasonic device of Patent Document 1, a reverberation reduction film is installed as an attenuation absorption film to cover the ultrasonic element. In a structure in which a plurality of ultrasonic elements are arranged, ultrasonic waves propagate through the attenuation absorption film. At this time, the ultrasonic element is affected by ultrasonic waves propagating through the attenuation absorption film. An ultrasonic element transmits ultrasonic waves. At this time, the ultrasonic wave transmitted by the ultrasonic element interferes with the ultrasonic wave propagating in the attenuation absorption film. The ultrasonic wave interference reduces the intensity of the ultrasonic wave transmitted from the ultrasonic element. Also, an ultrasonic element receives ultrasonic waves. At this time, the ultrasonic wave received by the ultrasonic element interferes with the ultrasonic wave propagating in the attenuation absorption film. The ultrasonic wave interference reduces the intensity of the ultrasonic wave received by the ultrasonic element. Therefore, there has been a demand for an ultrasonic device capable of transmitting or receiving ultrasonic waves with good quality even when the ultrasonic elements are arranged by reducing the propagation of ultrasonic waves along the damping absorption film that absorbs the vibration of the membrane.

An ultrasonic device of the present application includes a substrate on which ultrasonic elements that transmit ultrasonic waves in a first direction are arranged, and a reverberation reduction film that reduces reverberation vibration of the substrate is provided on the first direction side of the ultrasonic elements. and grooves are arranged between the adjacent ultrasonic elements in the reverberation reduction film.

In the above ultrasonic device, the material of the reverberation reduction film preferably contains silicone rubber.

In the ultrasonic device described above, it is preferable that the reverberation reduction film has a concave portion at a location facing the ultrasonic element.

An electronic device according to the present application includes a double feed detection device that is installed in a medium transport path and detects whether or not two or more media are overlapped, and the double feed detection device has the ultrasonic device described above. It is characterized by

An electronic device of the present application includes an ultrasonic transmitter that transmits ultrasonic waves, and an ultrasonic receiver that receives the ultrasonic waves transmitted by the ultrasonic transmitter, wherein the ultrasonic transmitter is the ultrasonic wave described above. It is characterized by having a sound wave device.

An ultrasonic device according to the present application includes a substrate on which ultrasonic elements for receiving ultrasonic waves traveling from a first direction side are arranged, and a reverberant vibration that reduces reverberant vibration of the substrate is provided on the first direction side of the ultrasonic elements. A reverberation reduction film is disposed, and a groove is disposed between the adjacent ultrasonic elements in the reverberation reduction film.

1 is a schematic plan view showing the structure of an ultrasonic device according to a first embodiment; FIG. FIG. 2 is a schematic plan view of a main part showing the configuration of an ultrasonic element; FIG. 2 is a schematic side cross-sectional view of a main part showing the configuration of an ultrasonic element; FIG. 2 is a schematic side cross-sectional view of a main part showing the configuration of an ultrasonic element; FIG. 4 is a schematic diagram for explaining ultrasonic waves propagating in a reverberation reduction film; Schematic diagrams for explaining a method for manufacturing an ultrasonic device. Schematic diagrams for explaining a method for manufacturing an ultrasonic device. Schematic diagrams for explaining a method for manufacturing an ultrasonic device. Schematic diagrams for explaining a method for manufacturing an ultrasonic device. Schematic diagrams for explaining a method for manufacturing an ultrasonic device. Schematic diagrams for explaining a method for manufacturing an ultrasonic device. Schematic diagrams for explaining a method for manufacturing an ultrasonic device. Schematic diagrams for explaining a method for manufacturing an ultrasonic device. Schematic diagrams for explaining a method for manufacturing an ultrasonic device. Schematic diagrams for explaining a method for manufacturing an ultrasonic device. FIG. 4 is a schematic plan view of a main part showing the configuration of an ultrasonic element according to a second embodiment; FIG. 2 is a schematic side cross-sectional view of a main part showing the configuration of an ultrasonic element; FIG. 2 is a schematic side cross-sectional view of a main part showing the configuration of an ultrasonic element; FIG. 4 is a schematic diagram for explaining ultrasonic waves propagating in a reverberation reduction film; FIG. 4 is a schematic side cross-sectional view for explaining the operation of the ultrasonic element; FIG. 4 is a schematic side cross-sectional view for explaining the operation of the ultrasonic element; FIG. 11 is a schematic side cross-sectional view showing the structure of a scanner according to the third embodiment; FIG. 11 is a schematic side cross-sectional view showing the structure of a printing apparatus according to a fourth embodiment; The block diagram which shows the structure of the distance measuring device concerning 5th Embodiment.

Embodiments will be described below with reference to the drawings.
In addition, each member in each drawing is illustrated with a different scale for each member in order to make it recognizable on each drawing.

(First embodiment)
In this embodiment, an example of a characteristic ultrasonic device and an example of a method for manufacturing the ultrasonic device will be described with reference to the drawings. An ultrasonic device according to a first embodiment will be described with reference to FIGS. 1 to 5. FIG. An ultrasonic device is a device also called an ultrasonic transducer device.

FIG. 1 is a schematic plan view showing the structure of an ultrasonic device. As shown in FIG. 1, the ultrasonic device 1 has a substrate 2 . The substrate 2 has a rectangular shape and two adjacent sides are perpendicular to each other. The direction in which one side extends is defined as the X direction, and the direction in which the side adjacent to the side in the X direction extends is defined as the Y direction. Let the thickness direction of the substrate 2 be the Z direction. External terminals 3 are arranged in the X direction on the −Y direction side of the substrate 2 .

A plurality of ultrasonic elements 4 are arranged in a matrix on the substrate 2 on the +Y direction side of the external terminal 3 . The numbers of rows and columns of the ultrasonic elements 4 are not particularly limited. When the ultrasonic device 1 is used as a sensor, it is preferable to have 10 to 100 rows and 10 to 100 columns. The intensity of ultrasonic waves can be sensitively detectable. In this embodiment, for ease of explanation, for example, the ultrasonic elements 4 are arranged in 15 rows and 15 columns.

The first to fifteenth external terminals 3 counted from the -X direction are signal terminals 3a. The ultrasonic elements 4 in each row and the signal terminals 3 a are electrically connected by signal wirings 5 . The terminal closest to the +X direction among the external terminals 3 is the common terminal 3b. A first common wiring 6 long in the +Y direction from the common terminal 3b is installed in the +X direction of each ultrasonic element 4, and the first common wiring 6 is a wiring long in the X direction on the +Y direction side of the ultrasonic elements 4. ing. The first common wiring 6 is branched at the +Y direction side of the ultrasonic element 4 and electrically connected to each ultrasonic element 4 . Each ultrasonic element 4 is connected to the common terminal 3b by the first common wiring 6. As shown in FIG.

FIG. 2 is a schematic plan view of essential parts showing the configuration of the ultrasonic element. 3 and 4 are schematic side cross-sectional views of main parts showing the configuration of the ultrasonic element. 3 is a cross-sectional view along line AA in FIG. 2, and FIG. 4 is a cross-sectional view along line BB in FIG. As shown in FIGS. 2, 3 and 4, the substrate 2 is formed with a recess 2a at a location facing the ultrasonic element 4. As shown in FIGS. The concave portions 2a are arranged in a matrix like the ultrasonic elements 4. As shown in FIG. The size of the concave portion 2a is not particularly limited, but in this embodiment, for example, it is a square with a side length of 150 μm to 250 μm. A portion between the concave portions 2a adjacent in the X direction and the Y direction is defined as a beam portion 2b. A portion of the beam portion 2b that is long in the X direction and a portion that is long in the Y direction are perpendicular to each other. The material of the substrate 2 is not particularly limited as long as it has strength and can be finely processed. In this embodiment, for example, a silicon substrate is used as the substrate 2 .

A vibrating film 7 is installed in contact with the substrate 2 on the +Z direction side of the substrate 2 , and the vibrating film 7 is a part of the substrate 2 . The vibrating film 7 is easily vibrated in the concave portion 2a. The material of the vibrating membrane 7 is not particularly limited as long as it has good vibration characteristics. In addition, it is preferable that the vibrating film 7 has insulating properties. In this embodiment, for example, silicon dioxide or zirconium dioxide is used as the material of the vibration film 7 . An insulating film may be provided on the vibrating membrane 7 when the vibrating membrane 7 does not have insulating properties. The diaphragm 7 is also called a membrane.

A lower electrode 8 , a piezoelectric body 9 and an upper electrode 10 are laid on the vibrating film 7 . An ultrasonic element 4 is composed of the lower electrode 8 , the piezoelectric body 9 and the upper electrode 10 . A driving voltage is applied between the lower electrode 8 and the upper electrode 10 . The drive voltage bends the piezoelectric body 9 . The ultrasonic element 4 transmits ultrasonic waves 12 in the Z direction in the figure. The Z direction in which the ultrasonic element 4 transmits the ultrasonic waves 12 is defined as a first direction 13 . Ultrasonic elements 4 for transmitting ultrasonic waves 12 in a first direction 13 are arranged on the substrate 2 . The ultrasonic elements 4 arranged on the substrate 2 can also receive the ultrasonic waves 12a traveling from the first direction 13 side. The lower electrodes 8 are covered with a piezoelectric body 9, and the lower electrodes 8 arranged in the Y direction are connected by wirings 11 shown in FIG. The wiring 11 is electrically connected through the signal wiring 5 to the signal terminal 3a.

Although the type of the piezoelectric body 9 is not particularly limited, a piezoelectric body such as a PZT (lead zirconate titanate) element or a PDVF (polyvinylidene fluoride) element can be used. In this embodiment, a PZT element is used as the piezoelectric body 9 . The material of the lower electrode 8 and the upper electrode 10 may be a conductive and stable material, and in this embodiment, for example, a film in which an iridium film and a platinum film are laminated is used. A PZT element can be stably formed on a platinum film.

A protective film 14 is arranged on the +Z direction side of the upper electrode 10 in the ultrasonic element 4 . The protective film 14 partially covers the piezoelectric body 9 , the lower electrode 8 and the upper electrode 10 . The protective film 14 prevents moisture from entering the piezoelectric body 9 and prevents dust from leaking between wirings. As the material of the protective film 14, an inorganic insulating film such as silicon oxide or aluminum oxide is used. In this embodiment, for example, aluminum oxide is used as the material of the inorganic insulating film that is the protective film 14 .

A reverberation reduction film 15 for reducing reverberation vibration of the substrate 2 is arranged on the first direction 13 side of the ultrasonic element 4 . The reverberation reduction film 15 is placed over the protective film 14 . The reverberation reduction film 15 reduces reverberation of vibration of the substrate 2 including the vibrating film 7 . The material of the reverberation reduction film 15 contains silicone rubber. Since silicone rubber has a small Young's modulus, the reverberation reduction film 15 can reduce reverberation vibrations without interfering with the movement of the substrate 2 including the vibrating film 7 and the ultrasonic element 4 .

A burst waveform is used for the drive voltage. In the burst waveform, sections of repeating rectangular waveforms and sections of DC waveforms are alternately combined. The ultrasonic element 4 vibrates in the section where the rectangular waveform repeats. The vibration of the ultrasonic element 4 is attenuated in the section of the DC waveform. When the vibration of the ultrasonic element 4 remains in the section of the DC waveform, the remaining vibration is combined with the vibration caused by the driving waveform in which the rectangular waveform is repeated. When the phase of the residual vibration and the phase of the vibration driven by the repeating rectangular waveform are out of phase, the strength of the vibration decreases.

The reverberation reduction film 15 reduces the vibration of the ultrasonic element 4 in the section of the DC waveform. Therefore, it is possible to reduce the residual vibration that lowers the strength of the vibration driven by the rectangular waveform.

The ultrasonic element 4 receives the ultrasonic waves 12a and vibrates. Also in this case, if the vibration is not attenuated after receiving and vibrating the ultrasonic wave 12a, it is synthesized with the vibration generated after a predetermined time has passed. Also at this time, when the phase of the residual vibration differs from the phase of the received vibration, the strength of the vibration decreases. Then, the reverberation reduction film 15 reduces the vibration of the ultrasonic element 4 in the section in which the ultrasonic wave 12a is not received. Therefore, the reverberation reduction film 15 can prevent the residual vibration from lowering the intensity of the vibration caused by the received ultrasonic wave 12a.

As shown in FIG. 3, on the +X direction side of the ultrasonic element 4 and the +Z direction side of the beam portion 2b on the -X direction side, the wiring 16 is arranged so as to overlap the vibrating film 7 . The wiring 16 is a wiring that is long in the Y direction. The material of the wiring 16 is the same as the material of the lower electrode 8 . The wiring 16 is formed in the same process as the lower electrode 8, but is electrically separated from the lower electrode 8. As shown in FIG.

A wiring 10 a is arranged so as to overlap with the wiring 16 . The wiring 10a electrically connects the upper electrodes 10 adjacent in the X direction. Furthermore, a second common wiring 17 is arranged so as to overlap with the wiring 10a. The second common wiring 17 is a wiring that is long in the Y direction. A wiring 10 a is arranged between the wiring 16 and the second common wiring 17 . The wiring 10 a electrically connects the wiring 16 and the second common wiring 17 to the upper electrode 10 . The same material as the upper electrode 10 is used for the wiring 10a. The wiring 16 and the second common wiring 17 are electrically connected through the first common wiring 6 to the common terminal 3b. Since the wiring 16 transmits an electrical signal together with the second common wiring 17, the wiring 16 has a lower electrical resistance than when only the second common wiring 17 is arranged.

A reverberation reduction film 15 is arranged on the +Z direction side of the second common wiring 17 . A reverberation reduction film 15 continues from the ultrasonic element 4 . Grooves 18 are arranged in the reverberation reduction film 15 between the adjacent ultrasonic elements 4 . The thickness of the reverberation reduction film 15 is thin where the groove 18 exists. Alternatively, there is no reverberation reduction film 15 in a place where the groove 18 is present.

As shown in FIG. 4, on the +Y direction side of the ultrasonic element 4 and the +Z direction side of the beam portion 2b on the -Y direction side, the wiring 16 is arranged so as to overlap the vibrating film 7 . The wiring 16 is a wiring that is long in the X direction. As with the beam portion 2b, the wiring 16 has a portion long in the X direction and a portion long in the Y direction perpendicular to each other.

A second common wiring 17 is arranged overlapping with the wiring 16 . The second common wiring 17 is a wiring that is long in the X direction. As with the wiring 16, the portion of the second common wiring 17 that is long in the X direction and the portion that is long in the Y direction are perpendicular to each other. Since the wiring 16 also transmits electrical signals in the Y direction together with the second common wiring 17, the wiring 16 has lower electrical resistance than when only the second common wiring 17 is arranged.

The reverberation reduction film 15 continues from the ultrasonic element 4 also in the Y direction. Grooves 18 are arranged in the reverberation reduction film 15 between the adjacent ultrasonic elements 4 . The thickness of the reverberation reduction film 15 is thin where the groove 18 exists. Alternatively, there is no reverberation reduction film 15 in a place where the groove 18 is present.

As shown in FIG. 2, the reverberation reduction film 15 has a quadrangular shape when viewed from above in the Z direction. Grooves 18 are arranged between the adjacent ultrasonic elements 4 in the reverberation reduction film 15 in both the X direction and the Y direction.

FIG. 5 is a schematic diagram for explaining ultrasonic waves propagating in the reverberation reduction film. As shown in FIG. 5, ultrasonic waves 12 are transmitted from the ultrasonic element 4 in the first direction 13 . A part of the ultrasonic wave 12 transmitted from the ultrasonic element 4 travels in a direction intersecting the first direction 13 . At this time, part of the ultrasonic wave 12 propagates through the interior of the reverberation reduction film 15 . Then, the ultrasonic wave 12 reaches the groove portion 18 . Air is contained in the groove 18 , and the refractive index of the groove 18 is significantly different from that of the reverberation reduction film 15 . That is, the propagation speed of the ultrasonic wave 12 differs between the reverberation reduction film 15 and the air.

Therefore, part of the ultrasonic wave 12 is reflected by the groove 18 and changes its direction. Some of the ultrasonic waves 12 are emitted into the air from the reverberation reduction film 15, and travel in multiple directions in the air. Therefore, it is difficult for the ultrasonic wave 12 to reach the ultrasonic element 4 adjacent to the transmitted ultrasonic element 4 . Therefore, the ultrasonic element 4 is less likely to be affected by the ultrasonic wave 12 transmitted by the adjacent ultrasonic element 4 . Therefore, even if the ultrasonic elements 4 are arranged, the ultrasonic waves 12 can be transmitted with good quality.

In the figure, the behavior of the ultrasonic wave 12 traveling in the X direction of the reverberation reduction film 15 has been described. Some of the ultrasonic waves 12 traveling in the Y direction of the reverberation reduction film 15 are also reflected by the grooves 18 . Some of the ultrasonic waves 12 are emitted into the air from the reverberation reduction film 15, and travel in multiple directions in the air. Therefore, it is difficult for the ultrasonic wave 12 to reach the ultrasonic element 4 adjacent to the transmitted ultrasonic element 4 . Therefore, the ultrasonic element 4 is less likely to be affected by the ultrasonic wave 12 transmitted by the adjacent ultrasonic element 4 . Therefore, even if the ultrasonic elements 4 are arranged, the ultrasonic waves 12 can be transmitted with good quality.

Also when the ultrasonic element 4 receives the ultrasonic waves 12 a , part of the ultrasonic waves 12 a reaching the reverberation reduction film 15 travels inside the reverberation reduction film 15 . At this time, some of the ultrasonic waves 12a are reflected by the groove 18 and change direction. Some of the ultrasonic waves 12a are emitted from the reverberation reduction film 15 into the air, and travel in many directions in the air. Therefore, it is difficult for the ultrasonic wave 12a to reach the ultrasonic element 4 adjacent to the ultrasonic element 4 that received the ultrasonic wave. Therefore, the ultrasonic element 4 is less likely to be affected by the ultrasonic wave 12a received by the adjacent ultrasonic element 4 . Therefore, even if the ultrasonic elements 4 are arranged, the ultrasonic waves 12a can be received with good quality.

Although the width of the groove portion 18 is not particularly limited, it is, for example, 30 μm or more and 40 μm or less in this embodiment. At this time, it is suppressed that the ultrasonic wave 12 propagates through the reverberation reduction film 15 and reaches the adjacent ultrasonic element 4 . Further, since the width of the groove portion 18 is narrow, it is possible to reduce the increase in the area of the ultrasonic device 1 .

6 to 15 are schematic diagrams for explaining the method of manufacturing the ultrasonic device. Next, a method for manufacturing the ultrasonic device 1 will be described with reference to FIGS. FIG. 6 is a schematic diagram for explaining the diaphragm installation process. As shown in FIG. 6, a base plate 21 is prepared. The base plate 21 is a silicon substrate. Then, a layer to be the vibrating membrane 7 is placed on the base plate 21 . First, a silicon oxide layer (SiO ₂ ) is laminated on the surface of the base plate 21, and a zirconium dioxide layer (ZrO ₂ ) is laminated on the surface of the silicon oxide layer. A sputtering method, a CVD (chemical vapor deposition) method, or the like is used as a method for laminating materials.

A lower electrode 8 and wiring 16 are placed on the vibrating membrane 7 . First, a metal film is placed on the vibrating film 7 . In this embodiment, for example, the metal film is a layer in which platinum is laminated on iridium oxide. Platinum is also called platinum. The method of installing the metal film is not particularly limited, but in this embodiment, the metal film is installed using, for example, a sputtering method.

Next, a photosensitive resist is placed on the metal film, and a mask having the shape of the lower electrode 8 and the wiring 16 is overlapped and exposed. Next, the photosensitive resist is removed by etching, and the resist is removed after the metal film is etched using the resist as a mask. As a result, the lower electrode 8 and the wiring 16 are placed on the vibrating membrane 7 .

7 to 9 are schematic diagrams for explaining the piezoelectric body installation process. As shown in FIG. 7, a pyroelectric material layer 22 is deposited. The pyroelectric material layer 22 is a layer that becomes the material of the piezoelectric body 9 and is a layer of a PZT film. The pyroelectric material layer 22 is deposited using a sputtering method or a sol-gel method. In the sputtering method, a PZT sintered body of a specific component is used as a sputtering target, and an amorphous piezoelectric film precursor film is formed on the vibrating film 7 by sputtering.

Next, this amorphous piezoelectric film precursor film is heated, crystallized, and sintered. This heating is performed, for example, in an oxygen atmosphere such as oxygen or a mixed gas of oxygen and an inert gas such as argon. In the heating step, the piezoelectric film precursor film is heated at a temperature of 500 to 700° C. in an oxygen atmosphere. The piezoelectric film precursor film is crystallized by heating.

In the sol-gel method, a sol, which is a hydrated complex of a hydroxide of titanium, zirconium, lead, or the like, which is the material of the pyroelectric material layer 22, is prepared. This sol is dehydrated to form a gel. This gel is heated and baked to prepare the pyroelectric material layer 22 which is an inorganic oxide. Starting materials are alkoxides or acetates of titanium, zirconium, lead, and other metal components. This starting material is a sol. This sol is used as a composition mixed with an organic polymer compound. This organic polymer compound absorbs the residual stress of the pyroelectric material layer 22 during drying and baking, and reduces the risk of cracks occurring in the pyroelectric material layer 22 .

Next, a sol composition is applied onto the vibrating membrane 7 . Various coating methods and printing methods are used for the coating method. After coating, the film of the sol composition is dried. Drying is performed by natural drying or by heating to a temperature of 80° C. or higher and 200° C. or lower. Next, the film of the sol composition is baked. The firing temperature is in the range of 300 to 450° C. and the firing is performed for about 10 to 120 minutes. A film of the sol composition is gelled by firing.

Next, the temperature is changed and re-fired. The sintering temperature is in the range of 400 to 800° C., and the sintering is performed for about 0.1 to 5 hours. Refiring involves a first step at a temperature in the range 400-600°C. A second step is then carried out at a temperature in the range of 600-800°C or less. As a result, the porous gel thin film is converted into a crystalline metal oxide film. When forming this film into a laminated film, the steps from application of starting materials to firing are repeated. Then pre-anneal.

As shown in FIG. 8, an upper metal film 23 is provided. In this embodiment, for example, the upper metal film 23 is formed by laminating an iridium film, a titanium film, and an iridium film in this order. The method of installing the upper metal film 23 is not particularly limited, but in this embodiment, it is installed using, for example, a sputtering method.

As shown in FIG. 9, the pyroelectric material layer 22 and the upper metal film 23 are patterned. A film made of the material of the mask film is placed on the upper metal film 23 . Then, a mask film is formed by patterning a film made of the material of the mask film by exposure and development using a photolithography method. Specifically, first, a photosensitive resist film is placed, and a mask having the shape of the piezoelectric body 9 is overlapped and exposed. Next, the resist film is removed by etching, and a mask film is provided. The shape of the mask film is the shape of the piezoelectric body 9 .

A portion of the pyroelectric material layer 22 is removed by dry etching using the mask film as a mask. By dry etching, the pyroelectric material layer 22 and the upper metal film 23 are etched into a square shape. Next, the mask film is removed using a remover.

Furthermore, the upper metal film 23 is patterned. A film made of the material of the mask film is placed on the upper metal film 23 . Then, a mask film is formed by patterning a film made of the material of the mask film by exposure and development using a photolithography method. Next, the resist film is removed by etching, and a mask film is provided. The shape of the mask film is the shape of the upper electrode 10 .

A portion of the upper electrode 10 is removed by dry etching using the mask film as a mask. By dry etching, the upper metal film 23 is etched into the shape of the upper electrode 10 . Next, the mask film is removed using a remover. As a result, the lower electrode 8 , the piezoelectric body 9 and the upper electrode 10 are laminated on the vibrating film 7 .

FIG. 10 is a schematic diagram for explaining the wiring installation process. As shown in FIG. 10, wiring 10a is installed. First, a metal film is formed. The metal film is a film that becomes the material of the wiring 10a. A method for forming the metal film is not particularly limited, but in this embodiment, for example, a sputtering method is used.

Next, a resin film made of a photosensitive material is formed on the metal film. Subsequently, the resin film is patterned by exposure and development using photolithography to form a mask film. The shape of the mask film is set to the shape of the wiring 10a. Next, the metal film is dry-etched using the mask film as a mask. As a result, the wiring 10a is formed from the metal film. Compared to wet etching, dry etching has a smaller amount of over-etching in the planar direction, so that a fine pattern can be formed with high accuracy.

11 and 12 are schematic diagrams for explaining the common wiring installation process. As shown in FIG. 11, a photosensitive resin layer 24 is provided. At this time, the thickness of the photosensitive resin layer 24 is adjusted so that the thickness dimension of the photosensitive resin layer 24 on the wiring 10 a becomes the thickness dimension of the second common wiring 17 . In this embodiment, for example, a positive photoresist is used for the photosensitive resin layer 24 . The thickness of the photosensitive resin layer 24 is, for example, 10 μm. This photosensitive resin layer 24 is exposed and developed to remove the photosensitive resin layer 24 at the location where the second common wiring 17 is to be formed. Then, a mask pattern is formed to form an opening 24a at a location where the second common wiring 17 is to be formed. Next, for example, by electroplating, Cu is deposited on the wiring 10a in the opening 24a to form the second common wiring 17. Next, as shown in FIG. After that, as shown in FIG. 12, the photosensitive resin layer 24 is removed. For example, a Ni layer or an Au layer may be formed on the surface of the second common wiring 17 by electroless plating.

FIG. 13 is a schematic diagram for explaining the protective film installation process. As shown in FIG. 13, a protective film 14 is provided. First, an inorganic film is placed over the upper electrode 10 , the wiring 10 a and the second common wiring 17 . The inorganic film is a film of aluminum oxide (Al ₂ O ₃ ) and is formed using the CVD method. Next, a resin film made of a photosensitive material is formed. Subsequently, the resin film is patterned by exposure and development using photolithography to form a mask film. Next, the inorganic film is dry-etched using the mask film as a mask. Subsequently, the mask film is removed. As a result, the inorganic film is formed in the shape of the protective film 14 .

14A and 14B are schematic diagrams for explaining the concave portion setting step. As shown in FIG. 14, the base plate 21 is patterned to form the recesses 2a. Specifically, a film made of the material of the mask film is placed on the surface of the base plate 21 on the -Z direction side. Then, a mask film is formed by patterning a film made of the material of the mask film by exposure and development using a photolithography method. The shape of the mask film is a planar shape in which the concave portion 2a is opened. Next, the base plate 21 is etched using the mask film as a mask. As an etching method, for example, anisotropic etching using an active gas such as wet anisotropic etching or parallel plate reactive ion etching is used to etch the base plate 21 . The vibrating membrane 7 functions as an etching stop layer. Next, the mask film is removed. As a result, the recess 2a is formed in the base plate 21. As shown in FIG. The substrate 2 is completed through the above steps.

FIG. 15 is a schematic diagram for explaining the step of installing the reverberation reduction film. Next, as shown in FIG. 15, the reverberation reduction film 15 is placed over the protective film 14 . First, a solid film of silicone rubber is laid over the reverberation reduction film 15 . A solid film indicates a flatly applied film. The solid film of silicone rubber is a photosensitive film. A solution in which a photosensitive silicone rubber material is dissolved is applied onto the protective film 14 of the substrate 2 . The coating method is not particularly limited as long as the solution is evenly coated in a predetermined amount. In this embodiment, for example, a spin coater was used to apply the solution. The solution is then dried to remove the solvent.

Next, a solid film of silicone rubber is masked with a predetermined pattern and exposed. The pattern of this mask is a pattern in which the grooves 18 are formed. Furthermore, the solid film of silicone rubber is etched and patterned. As a result, the reverberation reduction film 15 of silicone rubber is placed on the protective film 14 . As a method for installing the reverberation reduction film 15, precise screen printing may be used. The ultrasonic element 4 is completed through the above steps. Furthermore, the external terminal 3, the signal wiring 5 and the first common wiring 6 are formed on the substrate 2, and the ultrasonic device 1 is completed. The external terminal 3, the signal wiring 5 and the first common wiring 6 are formed in the order of deposition of a metal film, placement of a mask film, patterning of the mask film, etching of the mask film, etching of the metal film, and removal of the mask film. be. Through the above steps, the ultrasonic device 1 shown in FIG. 1 is completed.

As described above, this embodiment has the following effects.
(1) According to the present embodiment, the ultrasonic device 1 includes the substrate 2 on which the ultrasonic elements 4 are arranged. Each ultrasonic element 4 transmits ultrasonic waves 12 in a first direction 13 . A reverberation reduction film 15 is arranged on the first direction 13 side of the ultrasonic element 4 , and the reverberation reduction film 15 reduces the reverberation vibration of the substrate 2 . The presence of the reverberation reduction film 15 allows the ultrasonic element 4 to transmit the ultrasonic waves 12 with good responsiveness. Groove portions 18 are arranged in the reverberation reduction film 15 between the adjacent ultrasonic elements 4 .

A part of the ultrasonic wave 12 transmitted from the ultrasonic element 4 travels in a direction intersecting the first direction 13 . Then, it travels through the reverberation reduction film 15 and reaches the groove portion 18 . Air is contained in the groove 18, and the propagation speed of the ultrasonic wave 12 differs between the reverberation reduction film 15 and the air. Since the ultrasonic wave 12 is reflected by the groove 18, it is difficult for the ultrasonic wave 12 to reach the ultrasonic element 4 adjacent to the transmitted ultrasonic element 4. - 特許庁Therefore, the ultrasonic element 4 is less likely to be affected by the ultrasonic wave 12 transmitted by the adjacent ultrasonic element 4 . Therefore, even if the ultrasonic elements 4 are arranged, the ultrasonic device 1 can transmit the ultrasonic waves 12 with good quality.

(2) According to this embodiment, the material of the reverberation reduction film 15 contains silicone rubber. Since the Young's modulus of silicone rubber is small, the reverberation reduction film 15 can reduce the reverberation vibration without hindering the movement of the substrate 2 .

(3) According to the present embodiment, part of the ultrasonic wave 12a received by the ultrasonic element 4 travels in the direction intersecting the first direction 13 . Then, it travels through the reverberation reduction film 15 and reaches the groove portion 18 . Air is contained in the groove 18, and the propagation speed of the ultrasonic wave 12a differs between the reverberation reduction film 15 and the air. Since the ultrasonic wave 12a is reflected by the groove portion 18, it is difficult for the ultrasonic wave 12a to reach the ultrasonic element 4 adjacent to the ultrasonic element 4 from which the ultrasonic wave 12a is received. Therefore, the ultrasonic element 4 is less likely to be affected by the ultrasonic wave 12a received by the adjacent ultrasonic element 4 . Therefore, even if the ultrasonic elements 4 are arranged, the ultrasonic waves 12a can be received with good quality.

(Second embodiment)
Next, an embodiment of the ultrasonic device 1 will be described with reference to FIGS. 16 to 21. FIG. The difference of this embodiment from the first embodiment is that the reverberation reduction film 32 facing the ultrasonic element 4 has a concave portion. Description of the same points as in the first embodiment will be omitted. FIG. 16 is a schematic plan view of the essential part showing the configuration of the ultrasonic element. 17 and 18 are schematic side cross-sectional views of main parts showing the configuration of the ultrasonic element. 17 is a cross-sectional view along line CC in FIG. 16, and FIG. 18 is a cross-sectional view along line DD in FIG.

That is, in this embodiment, the ultrasonic device 31 has the substrate 2 as shown in FIGS. Ultrasonic elements 4 are arranged in a matrix on the substrate 2 . A reverberation reduction film 32 for reducing reverberation vibration of the substrate 2 is arranged on the first direction 13 side of the ultrasonic element 4 . The reverberation reduction film 32 is placed over the protective film 14 . The reverberation reduction film 32 reduces reverberation of vibrations of the substrate 2 including the vibrating film 7 and the ultrasonic element 4 . The material of the reverberation reduction film 32 contains silicone rubber. Since silicone rubber has a small Young's modulus, the reverberation reduction film 32 can reduce reverberation vibrations without interfering with the movement of the substrate 2 including the vibrating film 7 and the ultrasonic element 4 . A concave portion 33 is arranged in the reverberation reduction film 32 at a location facing the ultrasonic element 4 . In the concave portion 33, the reverberation reduction film 32 is thin or there is no reverberation reduction film 32. Therefore, since the ultrasonic waves 12 are allowed to pass through the concave portion 33 , the reduction in the sound pressure of the ultrasonic waves 12 due to the reverberation reduction film 32 can be reduced.

FIG. 19 is a schematic diagram for explaining ultrasonic waves propagating in the reverberation reduction film. As shown in FIG. 19, ultrasonic waves 12 are transmitted from the ultrasonic element 4 in the first direction 13 . A part of the ultrasonic wave 12 transmitted from the ultrasonic element 4 travels in a direction intersecting the first direction 13 . Even when the reverberation reduction film 32 has the concave portion 33 , part of the ultrasonic wave 12 propagates through the interior of the reverberation reduction film 32 . Then, the ultrasonic wave 12 reaches the groove portion 18 . Air is contained in the groove 18 , and the refractive index of the groove 18 is significantly different from that of the reverberation reduction film 32 . That is, the propagation speed of the ultrasonic wave 12 differs between the reverberation reduction film 32 and the air.

Therefore, part of the ultrasonic wave 12 is reflected by the groove 18 and changes its direction. Some of the ultrasonic waves 12 are emitted from the reverberation reduction film 32 into the air, and travel in multiple directions in the air. Therefore, it is difficult for the ultrasonic wave 12 to reach the ultrasonic element 4 adjacent to the transmitted ultrasonic element 4 . Therefore, the ultrasonic element 4 is less likely to be affected by the ultrasonic wave 12 transmitted by the adjacent ultrasonic element 4 . Therefore, even when the reverberation reduction film 32 has the concave portion 33, the ultrasonic waves 12 can be transmitted with good quality even if the ultrasonic elements 4 are arranged.

In the figure, the behavior of the ultrasonic wave 12 traveling in the X direction of the reverberation reduction film 32 has been described. Likewise, the ultrasonic waves 12 traveling in the Y direction of the reverberation reduction film 32 are also less likely to reach the adjacent ultrasonic element 4 . Therefore, even in the Y direction, the ultrasonic element 4 is less likely to be affected by the ultrasonic wave 12 transmitted by the adjacent ultrasonic element 4 .

Even when the reverberation reduction film 32 has the concave portion 33 , when the ultrasonic element 4 receives the ultrasonic wave 12 a , part of the ultrasonic wave 12 a reaching the reverberation reduction film 32 travels inside the reverberation reduction film 32 . At this time, part of the ultrasonic wave 12a is reflected by the groove 18 and changes its direction. Some of the ultrasonic waves 12a are emitted into the air from the reverberation reduction film 32, and travel in multiple directions in the air. Therefore, it is difficult for the ultrasonic wave 12a to reach the ultrasonic element 4 adjacent to the ultrasonic element 4 that received the ultrasonic wave. Therefore, the ultrasonic element 4 is less likely to be affected by the ultrasonic wave 12a received by the adjacent ultrasonic element 4 . Therefore, even when the reverberation reduction film 32 has the concave portion 33, the ultrasonic waves 12a can be received with good quality even if the ultrasonic elements 4 are arranged.

20 and 21 are schematic side sectional views for explaining the operation of the ultrasonic element. FIG. 20 shows the state when the ultrasonic element 4 moves in the first direction 13. As shown in FIG. FIG. 21 shows the state when the ultrasonic element 4 moves in the direction opposite to the first direction 13 . As shown in FIGS. 20 and 21, the deflection of the vibrating membrane 7 is small at the location where the piezoelectric body 9 is located and at the location where the beam portion 2b is located. Further, the deflection of the vibrating film 7 is large between the location where the piezoelectric body 9 is located and the location where the beam portion 2b is located.

The reverberation reduction film 32 is arranged from the surface facing the piezoelectric body 9 on the first direction 13 side to the surface facing the beam portion 2b on the first direction 13 side. At this time, the reverberation reduction film 32 is reliably arranged from the side surface of the piezoelectric body 9 to the side surface of the second common wiring 17 . Therefore, the reverberation reduction film 32 is arranged so as to cover the range where the vibration film 7 is largely bent. Therefore, the reverberation reduction film 32 can reliably reduce the reverberation of the vibrating film 7 .

In the figure, the structure on the X-direction side of the reverberation reduction film 32 has been described. The structure on the Y-direction side of the reverberation reduction film 32 is the same as the structure on the X-direction side. Accordingly, the reverberation reduction film 32 is arranged so as to cover the range in which the vibrating film 7 is greatly bent even on the Y direction side. Therefore, the reverberation reduction film 32 can reliably reduce the reverberation of the vibrating film 7 .

The vibrating film 7 also bends when the ultrasonic element 4 receives the ultrasonic waves 12a. At this time, the reverberation reduction film 32 is arranged to cover the range in which the vibration film 7 is largely bent. Therefore, the reverberation reduction film 32 can reliably reduce the reverberation of the vibrating film 7 .

As described above, this embodiment has the following effects.
(1) According to the present embodiment, the recess 33 is arranged in the reverberation reduction film 32 at a location facing the ultrasonic element 4 . In the concave portion 33, the reverberation reduction film 32 is thin or there is no reverberation reduction film 32. Therefore, it is possible to reduce the reduction in the sound pressure of the ultrasonic wave 12 by the reverberation reduction film 32 when the ultrasonic wave 12 is passed through the concave portion 33 .

(Third Embodiment)
Next, an embodiment of a scanner provided with the ultrasonic device 1 or the ultrasonic device 31 will be described with reference to FIG. 22, which is a schematic side sectional view showing the structure of the scanner. Description of the same points as in the first and second embodiments will be omitted.

That is, in this embodiment, as shown in FIG. 22, the scanner 41 as an electronic device is a device for reading an image drawn on a medium such as paper, and is also called an image reading device. The scanner 41 has a lower case 42 and an upper case 43 . The lower case 42 and the upper case 43 are connected by a hinge 44 so as to be openable and closable.

A cover portion 45 is rotatably attached to the lower case 42 on the upper right side of the lower case 42 in the drawing. The surface of the cover portion 45 on the side of the upper case 43 serves as a paper mounting surface 45a. A plurality of sheets 46 as media are placed on the sheet placement surface 45a. The paper 46 is rectangular, and a plurality of papers 46 have the same shape. An open feeding port 47 is arranged between the sheet mounting surface 45a and the upper case 43 . The paper 46 is transported into the scanner 41 from the feed port 47 .

The traveling direction of the paper 46 is assumed to be the -Y direction. The width direction of the paper 46 is defined as the X direction. The direction in which the sheets 46 are stacked is the Z direction. The X-direction, Y-direction and Z-direction are perpendicular to each other.

A discharge tray 48 is installed on the -Y direction side of the lower case 42 . A discharge port 49 that opens between the discharge tray 48 and the upper case 43 is arranged in the lower case 42 . The paper 46 enters the inside of the scanner 41 from the feed port 47 and is discharged from the discharge port 49 . The paper 46 discharged from the discharge port 49 is stacked on the paper discharge tray 48 . A transport path 50 for the paper 46 is a path along which the paper 46 moves from the paper placement surface 45 a to the paper discharge tray 48 . In the conveying path 50, the cover portion 45 side is defined as the upstream side, and the discharge tray 48 side is defined as the downstream side.

A feed roller 51 and a separation roller 52 are installed downstream of the feed port 47 . Gravity acts on the paper 46 placed on the paper placement surface 45a and moves it to the downstream side. Then, the edge of the paper 46 contacts the separation roller 52 . When the feed roller 51 rotates counterclockwise in the drawing, the paper 46 enters between the feed roller 51 and the separation roller 52 .

When only one sheet of paper 46 is sandwiched between the feed roller 51 and the separation roller 52 , the feed roller 51 and the separation roller 52 rotate together to transport the paper 46 . When two sheets of paper 46 are sandwiched between the feed roller 51 and the separation roller 52, the separation roller 52 rotates in a direction different from that of the feed roller 51 by a predetermined angle. When three or more sheets of paper 46 are sandwiched between feed roller 51 and separation roller 52 , feed roller 51 may convey two or more sheets of paper 46 .

A double feed detection device 53 is installed in the transport path 50 of the paper 46 downstream of the feed roller 51 and the separation roller 52 . A double feed detection device 53 is a device for detecting whether or not two or more sheets of paper 46 are overlapped. The double feed detection device 53 has an ultrasonic transmitter 54 and an ultrasonic receiver 55 . An ultrasound transmitter 54 transmits ultrasound waves 12 . An ultrasonic receiver 55 receives the ultrasonic waves 12 transmitted by the ultrasonic transmitter 54 .

As the number of sheets 46 increases, the intensity of the ultrasonic wave 12 passing through the sheets 46 decreases. The intensity of the ultrasonic wave 12 received by the ultrasonic wave receiver 55 is compared with the judgment value, and the double feeding detection device 53 detects whether the number of sheets 46 is one or two or more. The double feed detection device 53 has the ultrasonic device 1 or the ultrasonic device 31 . The ultrasonic device 1 and the ultrasonic device 31 are devices capable of transmitting and receiving the ultrasonic waves 12 with high quality even when the ultrasonic elements 4 are arranged. Therefore, the scanner 41 can be a device provided with the double feed detection device 53 in which the ultrasonic elements 4 that can transmit and receive the ultrasonic waves 12 with good quality even when arranged are arranged.

A conveying roller pair 56 is arranged downstream of the double feeding detection device 53 . The transport roller pair 56 includes a transport driving roller 57 and a transport driven roller 58 . A transport driving roller 57 and a transport driven roller 58 rotate with the paper 46 therebetween. Then, the transport roller pair 56 transports the paper 46 downstream.

An image reading device 61 is arranged downstream of the transport roller pair 56 . The image reading device 61 has a lower reading unit 62 and an upper reading unit 63 . The lower reading unit 62 reads the image written on the surface of the paper 46 on the -Z direction side. The upper reading unit 63 reads the image written on the surface on the +Z direction side. For example, a contact image sensor module (CISM) is installed in the lower reading unit 62 and the upper reading unit 63 .

A discharge roller pair 64 is arranged downstream of the image reading device 61 . The ejection roller pair 64 includes an ejection driving roller 65 and an ejection driven roller 66 . The ejection driving roller 65 and the ejection driven roller 66 rotate with the paper 46 therebetween. Then, the discharge roller pair 64 conveys the paper 46 to the discharge port 49 .

As described above, this embodiment has the following effects.
(1) According to this embodiment, the scanner 41 is provided with the transport path 50 . A multi-feed detection device 53 is installed in the transport path 50, and the multi-feed detection device 53 detects whether or not two or more sheets 46 are overlapped. The ultrasonic device 1 and the ultrasonic device 31 are used for the double feed detection device 53 . The ultrasonic device 1 and the ultrasonic device 31 are devices capable of transmitting and receiving the ultrasonic waves 12 with high quality even when the ultrasonic elements 4 are arranged. Therefore, the scanner 41 can be a device provided with the double feed detection device 53 in which the ultrasonic elements 4 that can transmit and receive the ultrasonic waves 12 with good quality even when arranged are arranged.

(Fourth embodiment)
Next, an embodiment of a printing apparatus provided with the ultrasonic device 1 or the ultrasonic device 31 will be described with reference to a schematic side cross-sectional view of FIG. 23 showing the structure of the printing apparatus. Description of the same points as in the first and second embodiments will be omitted.

That is, in this embodiment, as shown in FIG. 23, a printer 71 as an electronic device has a front paper feed tray 72 and a rear paper feed tray 73 . The front paper feed tray 72 is installed substantially horizontally at the bottom of the printer 71 . The rear paper feed tray 73 is arranged on the rear portion 71a of the printer 71 so as to protrude upward and to the right in the figure. Various sheets 46 are placed on the front paper feed tray 72 and the rear paper feed tray 73 .

Sheets 46 placed on the front paper feed tray 72 and the rear paper feed tray 73 are fed to a predetermined transport path. Then, the paper 46 is transported along the transport path and discharged to the paper discharge tray 74 arranged on the front portion 71 b side of the printer 71 . In the transport path, the front paper feed tray 72 and the rear paper feed tray 73 are defined as the upstream side, and the discharge tray 74 side is defined as the downstream side.

In the printer 71, there are a first transport path 75 for the paper 46 with the front paper feed tray 72 positioned upstream in the transport path, and a second transport path 76 for the paper 46 with the rear paper feed tray 73 positioned upstream in the transport path. exists. A transport path 77 is configured by the first transport path 75 and the second transport path 76 .

First, the transport of the paper 46 from the first transport path 75 will be described. A pick-up roller 78 is provided so that the outer circumference of the paper 46 placed on the top of the paper 46 placed on the front paper feed tray 72 is in contact with the paper 46 . The pickup roller 78 rotates counterclockwise in FIG.

The paper 46 is guided by the transport guide 79 at the right end in the figure. A portion of the transport guide 79 forms a curved transport path that draws a substantially semicircular shape. The paper 46 is guided by the transport guide 79 and advances toward the discharge tray 74 . The paper 46 is curved along the transport guide 79 and guided upward in the figure.

An intermediate roller 80 and an intermediate driven roller 80 a are provided in the middle of the curved path of the transport guide 79 . The intermediate roller 80 and the intermediate driven roller 80a rotate with the paper 46 therebetween. The intermediate roller 80 rotates clockwise in the figure. The paper 46 is further transported along the transport guide 79 by the rotational driving of the intermediate roller 80 .

A double feed detection device 81 is installed downstream of the transport guide 79 in the first transport path 75 for the paper 46 . A double feed detection device 81 detects whether or not two or more sheets of paper 46 are overlapped. The double feed detection device 81 includes an ultrasonic transmitter 81a and an ultrasonic receiver 81b. The ultrasonic wave receiver 81b receives the ultrasonic waves 12 transmitted by the ultrasonic transmitter 81a. The double feed detection device 81 has the ultrasonic device 1 or the ultrasonic device 31 . The ultrasonic device 1 and the ultrasonic device 31 are devices capable of transmitting and receiving the ultrasonic waves 12 with high quality even when the ultrasonic elements 4 are arranged. Therefore, the printer 71 can be a device provided with the double feed detection device 81 in which the ultrasonic elements 4 that can transmit and receive the ultrasonic waves 12 with high quality even when arranged are arranged.

A paper end sensor 82 is arranged downstream of the double feed detection device 81 in the first transport path 75 . The paper edge sensor 82 has a light-emitting portion and a light-receiving portion (not shown), and detects the leading edge of the paper by determining whether the paper 46 blocks the optical path between the light-emitting portion and the light-receiving portion.

A transport roller 83 and a transport driven roller 83 a are arranged downstream of the paper edge sensor 82 in the first transport path 75 . The transport roller 83 and the transport driven roller 83a sandwich the paper 46 and transport it to the downstream side.

A platen 84 and a carriage 85 are arranged downstream of the transport roller 83 in the first transport path 75 . The platen 84 supports the conveyed paper 46 from below in the figure. The carriage 85 is positioned above the platen 84 in the figure with the paper 46 interposed therebetween. The carriage 85 has a print head 85a on the lower side in the figure. A large number of nozzles are arranged and installed on the lower surface of the print head 85a in the drawing, and ink is ejected from each nozzle. Carriage 85 moves in a direction perpendicular to the plane of the drawing. The movement of the carriage 85 in this direction is called main scanning. The print head 85 a ejects ink onto the paper 46 while the carriage 85 performs main scanning. Then, the print head 85a can draw raster lines along the main scanning direction in the area facing the nozzles.

The printing position of the paper 46 can be shifted by conveying the paper 46 after main scanning. Conveying the paper 46 for drawing is called sub-scanning. By sub-scanning the paper 46 , raster lines can be drawn at different positions on the paper 46 . The printer 71 forms a print image on the paper 46 by sequentially repeating main scanning and sub-scanning. The paper 46 on which the print image is formed is discharged to the paper discharge tray 74 .

Next, the transport of the paper 46 on the second transport path 76 will be described. A hopper 88 is installed in the rear paper feed tray 73 . A load roller 86 and a load driven roller 87 are arranged downstream of the hopper 88 in the second transport path 76 .

The hopper 88 swings in a direction in which the downstream side of the rear paper feed tray 73 approaches the road roller 86 and in a direction away from the road roller 86 . As the hopper 88 approaches the load roller 86 , the top edge of the paper 46 on the rear paper feed tray 73 hits the load roller 86 and the paper 46 is sandwiched between the hopper 88 and the load roller 86 . By rotating the load roller 86 in this state, the paper 46 is sandwiched between the load roller 86 and the load driven roller 87 and conveyed downstream.

The paper 46 conveyed by the rotation of the load roller 86 passes through the double feed detection device 81 . The double feed detection device 81 is installed in the second conveying path 76 of the paper 46 and detects whether or not two or more papers 46 are overlapped.

Next, the leading edge of the paper 46 reaches the paper edge sensor 82 . Then, the leading edge of the paper 46 further transported toward the front surface portion 71 b by the rotation of the load roller 86 passes the paper edge sensor 82 and reaches the transport roller 83 . Paper 46 is transported onto platen 84 by transport rollers 83 . Main scanning of the carriage 85 and sub-scanning of the paper 46 are repeated to form a print image. A second transport path 76 is a path along which the paper 46 is transported from the rear paper feed tray 73 to the discharge tray 74 . A transport path 77 is configured by the first transport path 75 and the second transport path 76 .

As described above, this embodiment has the following effects.
(1) According to this embodiment, the printer 71 is provided with the transport path 77 . A multi-feed detection device 81 is installed in the transport path 77, and the multi-feed detection device 81 detects whether or not two or more sheets 46 are overlapped. The ultrasonic device 1 and the ultrasonic device 31 are used for the double feed detection device 81 . The ultrasonic device 1 and the ultrasonic device 31 are devices capable of transmitting and receiving the ultrasonic waves 12 with high quality even when the ultrasonic elements 4 are arranged. Therefore, the printer 71 can be a device provided with the double feed detection device 81 in which the ultrasonic elements 4 that can transmit and receive the ultrasonic waves 12 with high quality even when arranged are arranged.

(Fifth embodiment)
Next, an embodiment of a distance measuring device including the ultrasonic device 1 or the ultrasonic device 31 will be described with reference to the block diagram of FIG. 24 showing the configuration of the distance measuring device. Description of the same points as in the first and second embodiments will be omitted.

That is, in this embodiment, as shown in FIG. 24, a distance measuring device 91 as an electronic device has a control section 92 . The control unit 92 includes a CPU (Central Processing Unit) and memory, and programs and various data are stored in the memory. Then, the control unit 92 operates according to the program. A communication device 93 , an input device 94 and a display device 95 are connected to the control section 92 .

The communication device 93 is connected to an external device and receives signals output by the external device. Then, the controller 92 operates according to the input signal. Also, the communication device 93 outputs the measurement result to an external device. An input device 94 is configured by various switches and the like, and is a device for inputting an operator's instruction. The control unit 92 receives a signal from the input device 94 and operates according to the input signal. A display device 95 displays measurement conditions and measurement results. For example, a liquid crystal display device is used for the display device 95 .

A waveform forming circuit 96 and a time measuring circuit 97 are also connected to the controller 92 . A waveform forming circuit 96 is connected to a transmission driving circuit 98 and a time measuring circuit 97 . An ultrasonic transmitter 99 is connected to the transmission drive circuit 98 . The time measurement circuit 97 is connected to the reception drive circuit 100 . The reception drive circuit 100 is connected to the ultrasonic receiver 101 .

A waveform forming circuit 96 is a circuit for forming a drive waveform for driving the ultrasonic transmitter 99 . The waveform of the drive waveform is not particularly limited, but in this embodiment, for example, the drive waveform formed by the waveform forming circuit 96 is a burst waveform having a rectangular wave of 600 kHz. A transmission drive circuit 98 amplifies the drive waveform. The ultrasonic transmitter 99 inputs the amplified drive waveform and transmits the ultrasonic waves 12 toward the object 102 to be measured. The ultrasonic waves 12 transmitted from the ultrasonic transmitter 99 are reflected by the object 102 to be measured. A part of the reflected ultrasonic wave 12 a travels toward the ultrasonic receiver 101 . The ultrasonic wave receiver 101 receives the ultrasonic wave 12a transmitted by the ultrasonic wave transmitter 99 .

The ultrasonic receiver 101 receives the ultrasonic waves 12 a and outputs a voltage signal corresponding to the ultrasonic waves 12 a to the reception driving circuit 100 . A voltage signal corresponding to the ultrasonic wave 12a is assumed to be an ultrasonic signal. The reception drive circuit 100 receives an ultrasonic signal, amplifies it, and outputs it to the time measurement circuit 97 . The time measuring circuit 97 measures the time from when the waveform forming circuit 96 outputs the drive waveform to when the ultrasonic signal is input. The time measurement circuit 97 outputs the measured value of the measured time to the control section 92 .

In the control section 92, the CPU controls the operation of the distance measuring device 91 according to the program stored in the memory. The control unit 92 has various functional units for realizing functions. As specific functional units, the distance measuring device 91 has a distance conversion unit 103 and a display control unit 104 . The distance conversion unit 103 receives the measured value of time from the time measurement circuit 97 . Then, the distance conversion unit 103 multiplies the time measurement value by the velocity of the ultrasonic wave 12 . Then, the distance conversion unit 103 calculates the distance traveled by the ultrasonic wave 12 from the ultrasonic transmitter 99 to the ultrasonic wave receiver 101 via the object 102 to be measured. Further, the distance conversion unit 103 divides the traveled distance by 2 to calculate the distance from the ultrasonic transmitter 99 and the ultrasonic receiver 101 to the object 102 to be measured.

The display control unit 104 causes the display device 95 to display the value of the separation distance. Furthermore, the display control unit 104 causes the communication device 93 to output the value of the separation distance to an external device. The ultrasonic transmitter 99 and the ultrasonic receiver 101 have an ultrasonic device 1 or an ultrasonic device 31 . The ultrasonic device 1 and the ultrasonic device 31 are devices capable of transmitting and receiving the ultrasonic waves 12 with high quality even when the ultrasonic elements 4 are arranged. Therefore, the distance measuring device 91 can be a device in which the ultrasonic device 1 or the ultrasonic device 31 having the ultrasonic elements 4 capable of transmitting and receiving the ultrasonic waves 12 with good quality even if they are arranged. .

It should be noted that the present embodiment is not limited to the above-described embodiment, and various modifications and improvements can be made by those skilled in the art within the technical concept of the present invention. Modifications are described below.
(Modification 1)
In the fifth embodiment, the ultrasonic transmitter 99 and the ultrasonic receiver 101 had the ultrasonic device 1 or the ultrasonic device 31 . Either the ultrasonic transmitter 99 or the ultrasonic receiver 101 may have the ultrasonic device 1 or the ultrasonic device 31 . When the ultrasonic transmitter 99 has the ultrasonic device 1 or the ultrasonic device 31, the ultrasonic transmitter 99 is less susceptible to damage and can transmit the ultrasonic waves 12 with good performance. When the ultrasonic receiver 101 has the ultrasonic device 1 or the ultrasonic device 31, the ultrasonic receiver 101 is less susceptible to damage and can receive the ultrasonic waves 12a with good performance. This content can also be applied to the third embodiment and the fourth embodiment.

(Modification 2)
In the fifth embodiment, an example of the distance measuring device 91 having the ultrasonic device 1 or the ultrasonic device 31 is shown. Alternatively, the ultrasonic device 1 or the ultrasonic device 31 may be used as a proximity sensor that detects whether or not there is an object nearby. Even then, the proximity sensor can detect the object with good quality.

The contents derived from the embodiment are described below.

An ultrasonic device includes a substrate on which ultrasonic elements that transmit ultrasonic waves in a first direction are arranged, and a reverberation reduction film that reduces reverberation vibration of the substrate is arranged on the first direction side of the ultrasonic elements. A groove is arranged between the adjacent ultrasonic elements in the reverberation reduction film.

According to this configuration, the ultrasonic device includes the substrate, and the ultrasonic elements are arranged and installed on the substrate. Each ultrasonic element transmits ultrasonic waves in a first direction. A reverberation reduction film is disposed on the first direction side of the ultrasonic element, and the reverberation reduction film reduces reverberation vibration of the substrate. The presence of the reverberation reduction film enables the ultrasonic element to transmit ultrasonic waves with good responsiveness. The reverberation reduction film has grooves arranged between adjacent ultrasonic elements.

A part of the ultrasonic waves transmitted from the ultrasonic element travels in a direction intersecting with the first direction. Then, it travels through the reverberation reduction film and reaches the groove. Air is contained in the grooves, and the propagation speed of ultrasonic waves differs between the reverberation reduction film and the air. Since the ultrasonic waves are reflected by the grooves, it is difficult for them to reach the ultrasonic elements adjacent to the transmitted ultrasonic element. Therefore, an ultrasonic element is less likely to be affected by ultrasonic waves transmitted by adjacent ultrasonic elements. Therefore, even if the ultrasonic elements are arranged, ultrasonic waves can be transmitted with good quality.

In the above ultrasonic device, the material of the reverberation reduction film preferably contains silicone rubber.

According to this configuration, the material of the reverberation reduction film contains silicone rubber. Since the Young's modulus of silicone rubber is small, the reverberation reduction film can reduce reverberation vibrations without interfering with the movement of the substrate.

In the ultrasonic device described above, it is preferable that the reverberation reduction film has a concave portion at a location facing the ultrasonic element.

According to this configuration, the recess is arranged in the reverberation reduction film at a location facing the ultrasonic element. In the concave portion, the reverberation reduction film is thin or there is no reverberation reduction film. Therefore, it is possible to reduce the reduction in the sound pressure of the ultrasonic waves caused by the reverberation reduction film when the ultrasonic waves pass through the concave portion.

The electronic device includes a double feed detection device installed in a medium transport path and configured to detect whether or not two or more of the media are overlapped, and the double feed detection device includes the ultrasonic device described above. Characterized by

According to this configuration, the electronic device includes the transport path. A multi-feed detection device is installed in the transport path, and the multi-feed detection device detects whether or not two or more media are overlapped. The above-described ultrasonic device is used for the double feed detection device. The ultrasonic device described above is a device that can transmit and receive ultrasonic waves with high quality even if ultrasonic elements are arranged. Therefore, the electronic device can be a device having a double feed detection device having an ultrasonic device in which ultrasonic elements that can transmit and receive ultrasonic waves with good quality even when arranged are arranged.

The electronic device includes an ultrasonic transmitter that transmits ultrasonic waves and an ultrasonic receiver that receives the ultrasonic waves transmitted by the ultrasonic transmitter, and the ultrasonic transmitter is the ultrasonic device described above. characterized by having

According to this configuration, the electronic device includes an ultrasonic transmitter and an ultrasonic receiver. The ultrasonic device described above is used as the ultrasonic transmitter. The ultrasonic device described above is a device that can transmit and receive ultrasonic waves with high quality even if ultrasonic elements are arranged. Therefore, the electronic device can be a device that includes an ultrasonic device in which ultrasonic transmitters that can transmit ultrasonic waves with good quality even when arranged are arranged.

An ultrasonic device includes a substrate on which ultrasonic elements for receiving ultrasonic waves traveling from a first direction side are arranged, and a reverberation reduction film for reducing reverberation vibration of the substrate is provided on the first direction side of the ultrasonic elements. are arranged, and grooves are arranged in the reverberation reduction film between the adjacent ultrasonic elements.

According to this configuration, part of the ultrasonic waves received by the ultrasonic element travels in a direction intersecting with the first direction. Then, it travels through the reverberation reduction film and reaches the groove. Air is contained in the grooves, and the propagation speed of ultrasonic waves differs between the reverberation reduction film and the air. Since the ultrasonic waves are reflected by the grooves, it is difficult for them to reach the ultrasonic elements adjacent to the received ultrasonic element. Therefore, an ultrasonic element is less likely to be affected by ultrasonic waves received by adjacent ultrasonic elements. Therefore, even if the ultrasonic elements are arranged, the ultrasonic waves can be received with good quality.

DESCRIPTION OF SYMBOLS 1, 31... Ultrasonic device 2... Substrate 4... Ultrasonic element 12... Ultrasonic wave 13... First direction 15, 32... Reverberation reduction film 18... Groove part 33... Concave part 41... As an electronic device Scanner 46 Paper as medium 50 Conveyance path 53, 81 Double feeding detector 71 Printer as electronic device 91 Distance measuring device as electronic device 99 Ultrasonic transmitter 101 …ultrasonic receivers.

Claims (6)

A substrate on which a plurality of ultrasonic elements that transmit ultrasonic waves in a first direction are arranged,
The plurality of ultrasonic elements are arranged apart from each other,
Wiring is provided between the adjacent ultrasonic elements,
A reverberation reduction film for reducing reverberation vibration of the substrate is arranged on the first direction side of the ultrasonic element,
A groove is arranged between the adjacent ultrasonic elements in the reverberation reduction film ,
The ultrasonic device , wherein the groove is positioned on the wiring . The ultrasonic device according to claim 1,
The ultrasonic device according to claim 1, wherein the material of the reverberation reduction film includes silicone rubber. The ultrasonic device according to claim 1 or 2,
The ultrasonic device according to claim 1, wherein the reverberation reduction film has a concave portion facing the ultrasonic element. A multifeed detection device installed in a medium transport path and detecting whether or not two or more of the media overlap,
4. Electronic equipment, wherein the double feed detection device comprises the ultrasonic device according to claim 1. an ultrasonic transmitter for transmitting ultrasonic waves;
an ultrasonic receiver that receives ultrasonic waves transmitted by the ultrasonic transmitter,
An electronic device, wherein the ultrasonic transmitter comprises the ultrasonic device according to any one of claims 1 to 3. A substrate on which a plurality of ultrasonic elements for receiving ultrasonic waves traveling from the first direction side are arranged,
The plurality of ultrasonic elements are arranged apart from each other,
Wiring is provided between the adjacent ultrasonic elements,
A reverberation reduction film for reducing reverberation vibration of the substrate is arranged on the first direction side of the ultrasonic element,
A groove is arranged between the adjacent ultrasonic elements in the reverberation reduction film ,
The ultrasonic device , wherein the groove is positioned on the wiring .

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